


Petra's Test

by SpaceFish



Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/M, My First Smut, Oral Sex, Sex, Sexual Roleplay, Smut, Vaginal Sex
Language: English
Status: Completed
Published: 2021-02-28
Updated: 2021-02-28
Packaged: 2021-03-18 11:08:41
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,365
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29732970
Author URL: https://archiveofourown.org/users/SpaceFish/pseuds/SpaceFish
Summary: A married Petra and Byleth do a roleplay of their old academy days. Smut for a ship that needs more of it.
Relationships: Petra Macneary/My Unit | Byleth
Comments: 1
Kudos: 10





	Petra's Test

**Author's Note:**

> I typed this up in Word, and it warned me that the words “Fuck” and “Clit” may offend my readers. So I apologize if you were hoping there’d be no bad words in this crappy porn fanfic. Also crappy is offensive, apparently. So sorry about that.

“Professor, may I have a moment?”

Byleth looked up from the mountain of papers on his desk. “Of course Petra.”

Petra approached Byleth’s desk with a piece of paper in hand. Her fishtail braid draped directly behind her back. “I have been struggling with mathematics. It has been giving me great difficulty.”

“Do you need me to give you some tutoring?” Byleth asked. “I would be happy to give you some one-on-one time.”

“Well, yes, one-on-one time is what I am wanting” Petra replied as she reached his desk. She leaned forward to put the paper she was holding on his desk right in front of him. But instead of leaning back once she had, she put her hands on the desk and looked him in the eyes, her face a few inches from his. “But not for tutoring. I am thinking there might be another way to fix my grade.”

Byleth blushed slightly as Petra held eye contact, biting her lower lip. Just a few inches away, he could feel her hot breath on his face. He pushed his chair back slightly and glanced downwards, noticing how tightly her uniform clung to her body. Seeing this, Petra straightened up off the desk, giving Byleth a better view. A view Byleth could hardly believe. Sure, the war and natural aging had made Petra more muscular than she was in her school days, but her white button-up shirt was clearly much too small for her. In fact, Byleth was surprised that academy uniforms that small even existed. Her large breasts pushed against the white top as the poor buttons struggled to keep them from bursting out. Her perfectly tan skin was visible between each button. He could see the faint outline of her nipples through the thin fabric. Moving his gaze downward, he noticed her shirt ending right at her bellybutton, letting Byleth see plenty of skin between it and her skirt. Well, it was generous to call it a skirt. It covered everything that it needed to, but only barely, leaving almost all of her muscular thighs revealed. That was definitely not standard academy size. “Well Miss Macneary” he finally stammered, turning his attention back to her face, noticing her blush and her smirk. “What exactly did you have in mind?” “I am thinking that you should give me an A.”

Byleth gave a smile, leaning back in his chair. “An A? You’re going to have to give me a good reason to do that.”

“I am having a good reason” Petra replied. Her hands went up to undo the top button on her shirt. One-by-one, she went down slowly undoing each button, watching Byleth’s face as she did. As she undid her shirt, her large breasts pushed forwards and spread out, finally free from their cotton constraints. Byleth felt his temperature rise as he watched her shirt part down the middle, revealing her chest in its entirety. Evidently, Petra had not worn a bra to class today. Done unbuttoning, Petra brought her hands up to the underside of her breasts, giving them a light squeeze. “In fact, I am having two good reasons.”

Byleth couldn’t help but stare at her boobs, mesmerized. Each was perfectly round and the same well-tanned tone as the rest of her body. Her light brown nipples, while a little on the small side, were located right in the center of her breasts. Despite their size, Petra’s tits were surprisingly perky. Sure, her current hand position was helping, but there was no faking a shape or size that magnificent. Between her breasts was a tattoo of the Brigid symbol for love, matching the one he had gotten when they got married. Moving his gaze downward, Byleth admired her perfect body. Her waist was slim and muscular. While the end of the war months earlier meant that her abs had lost some definition, she maintained a six-pack. If Byleth had a heartbeat, it would have been beating rapidly.

“Well, those are two compelling reasons” Byleth finally stammered, looking up at Petra’s amused face. She was clearly enjoying the attention. “But I’m going to need to examine them more thoroughly to give you a passing grade.”

“Of course, professor” she replied. Dropping her hands to her sides and letting her shirt fall to the ground, Petra slowly began to walk around Byleth’s desk. Her first steps took her to her right, away from him, and he noticed that his initial assessment had been wrong; her skirt wasn’t long enough to cover everything. As she reached the end of his desk and turned back towards him, Byleth turned his chair so that he was facing her, parallel to his desk. Petra, finally reaching him, took a seat on his lap and straddled him with her muscular legs. She wrapped her hands around his head, using her left hand to stroke the back of his neck and her right to gently grip his hair. He wrapped his arms around her waist, placing his bare hands on the small of her back. Petra adjusted her body position, making sure to grind against his crotch as she did. She felt some stiffness and heard him emit a small grunt, but he was not quite ready yet.

The two were roughly face-to face, but in their current position, Petra had a slight height advantage. Byleth gave her neck a few quick kisses, to which Petra responded with some light moans. “Lean back” he ordered. Petra obliged, keeping her hands cradled around his head but extending her arms and arching her back. This gave him a great view of her bare chest, just a few inches away. “Hmm...those do seem to be pretty good reasons” Byleth stated, staring at her perfect nipples. He took his right hand from around her waist and brought it up to her left boob. He cupped it, stroking her nipple with his thumb before giving it a light squeeze. Petra gave a slight moan at the action. Byleth then moved his eyes back up to his wife’s face. She had been looking down at her breasts as Byleth continued to stroke her nipple, but quickly glanced up to meet his gaze. She was blushing but her expression was full of desire. She wanted him to continue.

“I am glad that you like them” Petra said, voice full of desire. “But are you needing a closer look?”

“I think that would be a good idea” he said. Byleth leaned forward until his face was level with Petra’s breasts, maintaining eye contact. With his hand already on her left breast, he moved his mouth towards it, planting light kisses on top of it. He lifted it up so he could lick her nipple, giving it several long, sensual strokes with his tongue. Petra closed her eyes and whimpered as a shudder went through her body. Byleth then put as much of her tit into his mouth as he could and began to suck while continuing to stroke her nipple with his tongue. 

“Oh…yes it feels so good my love!” Petra cried, short on breath. Byleth’s mouth felt amazing against her sensitive nipple, and she moaned in delight. She opened her eyes and looked downwards to see at her husband’s face. Making eye contact, Byleth gave a pleased moan. Well, as much of moan as he could with his mouth full. This gave made Petra shudder with delight yet again. She could feel his manhood pushing against his pants has she shifted her hips. Her hands clenched on the back of his head, grabbing handfuls of his green hair. Petra closed her eyes again, wanting to focus on the sensation. Byleth was making her feel so fucking good. But suddenly, he stopped.

“Wait a minute” he said with faux confusion. “My love?”

“What?” Petra said, opening her eyes. Byleth was staring back at her, mischievous look on his face. “Fuck” she said, realizing her mistake. “I mean, professor. It feels so good professor!”

Byleth smiled and used his left hand to pull Petra forward. “That’s better” he said before pressing his mouth onto hers. Closing her eyes again she opened her mouth and let her tongue become entwined with his. Byleth moaned, which excited Petra even more. He used his right hand to gently squeeze her boob. His erect penis could feel her crotch grind against his. She had apparently neglected to wear panties as well, and he could feel just how wet she was, how much she wanted him. He finally parted his lips from hers, gently using his right hand to push her back so he could look into her beautiful brown eyes. “Your first reason was good,” he said, panting. “But let’s check the second.”

“Of course Professor” Petra replied. Like him, she was struggling to catch her breath. She leaned back again so that Byleth could easily access her right breast. He kept his hand on her left breast, rubbing her nipple with his thumb. He then leaned in and made out with her right boob, much more aggressive than he had been with her left. Petra managed to let out an exasperated “Professor” as Byleth’s lips and tongue rapidly covered the area around her nipple. “Yes...yes…Sprits yes…” Petra moaned.

Byleth alternated sucking and licking Petra’s voluptuous breast. Her body tasted amazing to him, and he could feel her movement start to tense up. He tasted the tattoo between her tits before guiding his tongue back to her nipple. He could tell she was close, and despite still being fully clothed, he was too. But he was suddenly struck with a thought. He was better than this. He couldn’t do this. He couldn’t let a student sleep with him for a better grade! No, he was a professor of Garreg Mach, dammit! Well, he actually wasn’t, but he used to be, and was currently pretending to be, and that’s good enough for him!

He pulled his head back and looked at Petra. She opened her eyes and looked at him, short on breath. She had begun to rock her hips back and forth on his crotch. “More professor, you are filling me with happiness!” She closed her eyes and titled her head back.

“Miss Macneary!” Byleth said with an intensity that surprised even himself. Startled by his harshness, Petra stopped her body movements and opened her eyes. He was trying to look serious, but Petra could tell he was struggling. After taking another second to catch his breath, he continued “I am your professor! I have to uphold this school’s reputation, and my own integrity!”

Petra gave him a confused look. They had not planned this part beforehand “Integrity?” she asked. She examined Byleth’s face. It had some intensity, but he was still panting, and his eyes remained full of lust. “Oh, I have understanding!” Petra declared excitedly. She shifted her body backwards slightly and slid her right hand from the back of his neck down to his crotch. She rubbed his bulge, still restrained by his pants, admiring it as she did. 

“This is your integrity!” She said grasping his penis as well as she could through his pants and stroking it. Looking back up at his face, she could see him desperately struggling to maintain his stern expression. “I shall be having a close conversation with it!” Petra pushed herself off of his lap and sank to her knees.

“That’s not-” Byleth began to protest before changing his mind. He could try to take a stand later. Concentrating on her task, Petra undid his belt before pulling down his pants. Byleth shifted to make the task easier for her. Petra looked up at his face, noticed that the stern façade he had struggled to maintain was completely gone now. His eyes were closed, his breathing was heavy, and he shuddered in anticipation of what would come next. Petra reached towards his now uncovered cock, grasping it her right hand while moving her left under her skirt. She would get both of them off.

Byleth’s penis stuck straight upwards, excited to finally be free. Petra loved Byleth’s cock. It was long and smooth, large enough to satisfy her without being uncomfortable. She leaned forward and planted some light kisses on its head. Focusing fully on his cock, she put all of the head into her mouth, caressing it with her tongue while rubbing the base with her hand. “Mmm” she mumbled to let Byleth know she enjoyed his taste. As she did, she rubbed her clit. She circled it with her index finger and shuddered at the sensation. Glancing up at her husband, she saw his face was red and heard him moan in pleasure as she sucked on the top of his dick. He opened his eyes and they made eye contact, and Byleth gently gripped the base of her ponytail.

“I’m almost there!” He cried.

Encouraged, Petra bobbed her head downwards, fitting nearly all of Byleth’s shaft in her mouth, before pulling back up the head. She repeated that motion, falling into a rhythm. At the same time, Petra used her index and middle fingers to rapidly rub her clitoris. She could feel he was about to climax. She was making both of them feel so good. “Petra…Petra…Petra…” Byleth managed to get out between rapid breaths. That was enough for Petra. Her body tightened as she began to feel pure ecstasy spread throughout it. She pushed her head off of Byleth’s cock and closed her eyes. Unrestrained, she moaned as her body seized with pleasure. Hearing his wife orgasm sent Byleth over the edge. He felt the hot sensation of climaxing spread from cock and balls to the rest of his body. His erect penis pumped forward shooting out cum, the first wave landing on Petra’s face, covering her tattoo in white. Byleth moaned as he pumped out more semen, most of it landing on Petra’s cheek or flying over her shoulder. His wife barely seemed to notice, her body still seizing as she enjoyed her own orgasm. Byleth still held her braid, keeping her steady as she moaned in ecstasy. She continued to writhe in delight, one hand still under her skirt and the other on Byleth’s thigh. After many more seconds of pleasurable cries, her breathing began to slow back down.

When she eventually came down, he gave her a few seconds to catch her breath before gently pulling up. She opened her eyes and looked into his, not ready to be done. Byleth stood up, bringing her with him, as his pants slumped to the floor.

“Love…I mean, Petra,” Byleth had to stop to catch his breath. Pretending to be the stern teacher was much harder after cumming on his “student’s” face. His face was red, and his expression was much softer than it had been. “It’s a serious ethics violation to try to seduce your professor for a better grade” he declared, looking her in the eyes. “I can’t change the grade on your math test!”

“It was a history test” Petra replied between breaths.

“I thought it was math?”

“Please do not be bringing up math during sex.”

Byleth couldn’t help but laugh at the conviction in her voice. Petra giggled as well, and pressed against him for a quick kiss before stepping back. Releasing his grip on Petra’s braid, Byleth grabbed the paper she left on his desk. The paper had a big red ‘F’ at the top of it, but Byleth read below it:

 _I love you._  
_Please fuck me hard._  
_Love Petra._

“Hm…yes, this does seem to be a history paper” Byleth said still chuckling, turning his attention back to a slightly annoyed Petra. He handed her the test, which she used to wipe her face then discarded onto the floor. He probably wasn’t going to review that paper again. “But this is still a serious ethics violation. You’ll need to be punished.”

“Oh yes, a punishment!” Petra exclaimed, her face lighting up. She finally understood where he was going before he was distracted by his integrity. “I am deserving of a harsh punishment!”

“I’m glad you agree” Byleth replied. He hastily shoved the papers off of his desk. He’d deal with the cleanup later. He gently grabbed the base of Petra’s braid and directed her so that she was leaning far forward. Byleth pressed her bare chest pressed against the desk as he released her braid. Her head hung over the desk from this angle, but it was long enough for most of her torso.

Petra looked her husband in the eyes as she smiled in anticipation. Her breasts squished against the desk, she used her hands to pull up her skirt so that her ass was completely uncovered. She saw Byleth turn his attention to it as he was momentarily stunned by her body. Her ass was tan and firm, her pussy was tight and wet. Once again, Petra blushed and felt a heat rise throughout her body. It was clear how badly he wanted her, and even with his games, despite his mental endurance, Petra knew that her husband couldn’t resist fucking her properly much longer. But, he may need a reminder. 

“I am ready to be punished” she said, finding it adorable as Byleth refocused on her face, struggling to regain his composure. 

“Of course” Byleth replied, admiring his wife’s sexy smirk before returning his focus to her uncovered ass. It was far from the first time he had seen it, but it still mesmerized him. The perfect tan, the perfect shape, the perfect pussy right below it. It was…well, perfect. And, best of all, it was waiting for him. He couldn’t help but give her right butt cheek a squeeze before focusing on punishment. Byleth, standing on Petra’s right, gently pressed his left hand on her back and used his right to give Petra’s ass a firm slap.

Petra gave a small grunt of delight. “Yes professor, more!” she cried. Byleth complied, and she gave a pleased whimper after each slap. Alternating cheeks, Byleth was firm without being too harsh, leaving her with a persistent pleasant sting. But still, it was only a few spanks before she had had enough. “Mmhh…I am feeling very punished.”

“I'm sorry Miss Petra, it seems I've punished you a little too harshly" Byleth replied, releasing his hand off her back. His voice seemed to have some genuine concern that he’d harmed her.

“I am thinking that was the perfect amount of punishment” she replied, trying to reassure him. 

Byleth gently placed a hand on her lower back, looking her in the eye. “No” he said. “Let me make it up to you.” 

“I am feeling good” Petra insisted. As she watched Byleth smile and drop to his knees, she realized what he was doing. “I mean, no, I am needing apologies” she said as she smiled in anticipation, once again facing forward.

“Well then let me apologize.” Byleth planted a kiss on each of her ass cheeks where he had spanked her. He then shifted his gaze to what was between them. He looked at her pussy, tight and wet. He pressed his face against her tight ass, putting his mouth right on her vagina. He started with a few gentle kisses, continuing when he heard Petra’s encouraging feedback. He gently flicked his tongue ins and out of her, before pressing it all the way into her pussy, hearing her release a pleased moan as he did. He swirled it around, tasting as much of her as he could. Damn she tasted good! He moaned to let her know. Petra gripped the edge of the table and shifted her hips. This was the best she had felt so far tonight. Byleth shortly worked his way down to her sensitive clitoris, and began to rub it with his tongue. He wrapped his arms around her thighs, caressing them. He could feel her balance faltering.

After only a minute of stroking her clit with his tongue, Petra’s orgasm started. She closed her eyes as her body pulsed with the wonderful sensation. Her knees grew weak, she may have slid off the table if not for Byleth’s grip on her thighs. Her moans were louder this time, as the sensation of Byleth’s tongue was stronger than her own fingers. Her muscular body tensed and released, tensed and released, as she felt waves of ecstasy wash over her. Byleth pulled his head back slightly, his tongue strokes now gentle and shallow as his wife squirmed. He could feel her body shiver, hear her delighted moans. He held her thighs and kept gently licking her pussy as she began to slow.

“By…Byleth…My Love…” Petra managed to get out between short, exasperated breaths.

“Hmm?” he responded, still licking her pussy.

Petra shifted her legs up, forcing Byleth away, and rolled onto her back. He stood up and admired her body. Her tits were bobbing up and down with each heavy breath. Sweat clung to her toned abs. He looked her in the eyes and noticed that she still looked hungry for him. “Take me, my Love.”

That was all the invitation he needed as he took the chance to finally take off his shirt, giving Petra a good look at him body. The war had left him with strong muscles and small scars on his pale skin. Petra's eyes travelled up from his cock to his six-pack abs to the tattoo over his heart. His body was incredible, and she wanted it to make love her. She spread open her legs and wrapped them around Byleth, pulling him forward. He reached out and fondled her breasts, one in each hand, while rubbing his crotch against hers. He was not inside her yet, content to rub his cock on her thighs and lower abdomen, teasing her. Byleth leaned forward and planted a kiss on her chest tattoo, the one that symbolized their love. He leaned back and used one hand to gently rub her wet pussy. She writhed and whimpered in delight. After a few strokes, he used his hand to grab his cock and direct it inside of her. 

Petra whimpered when she finally felt all of Byleth inside of her. His cock strokes the sensitive walls of her vag as he began to thrust back and forth. She closed her eyes and let out a moan as she felt her husband’s strong hands wrap around her waist. Her body felt hot as she felt him began to thrust with more confidence, giving out light grunts as he did. The movement of his hard cock felt great inside her, and Petra maneuvered her hips in rhythm with him. Her breasts bounced with each stroke, giving Byleth another mesmerizing view. 

“…Byleth…I...I…I’m almost…” short on breath, Petra couldn’t finish her sentence. The sensation she felt of white-hot pleasure was not just physical. The pleasurable movements of his cock inside her pushed her towards orgasm; but their emotional connection, their love for each other, the roles they were playing, put them close together. She heard him cry out her name, felt him cum inside her. They were two people, but at that moment, Petra and Byleth were one. She surrendered to that completeness, letting the sensation wash over her. Her voice cried out as her body and mind were consumed by pleasure. She writhed and moaned in pure ecstasy. Wave after wave of fullness, joy, and delight came over her before eventually slowing to an end.

Byleth sat on his desk next to where Petra was laid out. She lifted rotated her body 90 degrees so that she was completely on the desk, her head in his lap as she looked into his mesmerizing blue eyes. He held her gaze and stroked her hair as they both panted. They held that position for many minutes before Petra broke the silence.

“I have been having that fantasy since our first language lesson.”

Byleth smiled “Was it worth the wait?”

Petra gave him a loving smile. “Of course, my Love.” She sat up and gave him long, passionate kiss. She felt his muscular arm wrap around her for balance. She placed a hand on the middle of his chest, right on his tattoo. That was the physical mark of their love, but their love was much more than that; emotional, mental, sexual, spiritual. It was here, in each other’s embrace, that they felt complete.

Petra broke off the kiss and pushed herself off the desk. She grabbed a long black academy uniform from a nearby desk and used it to cover herself. She turned to look at Byleth. “Well Professor, I am hoping that you will reconsider my math grade.”

Byleth gave her a smile. “Well Petra, I might need more convincing at a later date.” 

“I have confidence we can arrange something” she replied with a smile. Leaning over to give him one more quick kiss, Petra turned and walked out the door. She hesitated before heading out, cautious to avoid being seen in her current attire. But she had been trained in stealth and it was late at night, so Byleth was confident she could make it back to their room undetected. He wasn’t as confident about himself staying hidden. He should probably get dressed. He stood up off the desk when what she said finally hit him.

“Wait...Did she say math grade?” he asked himself, reaching for his pants. “So it was a math test!”

###### 

With his pants back on, Byleth sat back on his chair and took a deep breath. 

“Uh Professor…may we be excused please?” Dorothea asked, meekly raising her hand. Byleth looked out onto the rest of his class. Most had some mix of embarrassment and horror on their faces. He wasn’t sure Bernadetta would ever recover.

“Uh…yeah sure. I’ve got some papers to grade.”

The Black Eagles quickly shuffled out of the classroom. Once they were a good distance away Caspar began to panic. “Oh Goddess” he exclaimed. “What if he finds out I’m failing math?”

**Author's Note:**

> I couldn't help myself with the ending lol. You can consider “So it was a math test!” the real end, but I guess you don't have to if you're weird like that. Thank you for reading. Have a nice day.


End file.
